Device for cleaning magnetic filters

ABSTRACT

A magnetic filtering device in which propeller means are interposed between serially arranged magnetic grates and are adapted to be rotated to impart a high-velocity flow upon liquid surrounding the magnetic grates.

United States Patent [72] Inventor Joachim Taeger Rheinhausen, Germany[21] Appl. No. 28,301

[22] Filed Apr. 14, 1970 [45] Patented Jan. 4, 1972 [73] Assignee Fried.Krupp Gesellschafl mit beschrankter I-Iaitung Essen, Germany [32]Priority May 3, 1969 [3 3] Germany [54] DEVICE FOR CLEANING MAGNETICFILTERS 4 Claims, 1 Drawing Fig.

[52] US. (I 210/222,

[51] Int. Cl B036 1/30 [50] Field of Search 210/222, 223, 327, 332, 333,353, 354, 391

[56] References Cited UNITED STATES PATENTS 969,364 9/1910 Gootenhuis210/354 3,326,374 6/1967 Jones 210/222 Primary ExaminerReuben FriedmanAssistant Examiner-T. A. Granger Attorney-Walter Becker ABSTRACT: Amagnetic filtering device in which propeller means are interposedbetween serially arranged magnetic grates and are adapted to be rotatedto impart a high-velocity flow upon liquid surrounding the magneticgrates.

DEVICE FOR CLEANING MAGNETIC FILTERS The present invention relates to adevice for cleaning magnetic filters. It has already been suggested toclean magnetic filters of ferromagnetic substances deposited on themagnetic parts of the filters by moving the magnets relative to thesurrounding water at such a high speed that the magnetic deposits aretorn off the magnetic parts of the filter. The torn off deposits canthen by scavenging water be washed out from the magnetic filter. Thismethod, however, has the drawback that considerable energy is requiredin order to rotate the rather heavy magnetic system at correspondinglyhigh speeds. For instance, the known method is carried out in a devicein which within a pressure body there is provided a permanent magnetsystem on a rotatable shaft which permanent magnet system is at astandstill during normal operation so that the magnetic impurities inthe water can deposit or collect on the filter. For purposes of cleaningthe filter, it is however necessary to rotate the magnetic system at ahigh speed for which purpose considerable power is required.

It is, therefore, an object of the present invention to provide a devicefor cleaning the magnetic filters which will overcome theabove-mentioned drawbacks.

For purposes of realizing the above-outlined object, it is suggestedaccording to the present invention for purposes of removing thedeposited ferromagnetic material collected on the magnetic system atrelatively low water speed, to permit the magnetic system to rest and torotate the surrounding water at such a speed that the ferromagneticsubstances deposited on the magnets will be torn off from the latter.More specifically, the device according to the present inventioncomprises a plurality of magnetic systems arranged one above the otherin spaced relationship to each other while between the individualmagnetic systems propellers or blades are rotatably arranged which forpurposes of cleaning the magnetic system are rotated at relatively highspeed so as to impart upon the surrounding water such a speed that theferromagnetic substances deposited on the magnetic system will be tornoff from the latter and can be withdrawn from the filter by scavengingfluid.

It will be appreciated that in this way with the device according to theinvention, no major masses have to be accelerated. The propellers orblades can easily be turned and the power consumption is low so that thedriving device and, if necessary, transmissions pertaining thereto canhave small dimensions and can be light in weight.

This object and other objects and advantages of the invention willappear more clearly from the following specification in connection withthe accompanying drawing diagrammatically illustrating a verticalsection through a magnetic filter according to the present invention.

Referring now to the drawing in detail, the arrangement shown thereincomprises a pressure resistant housing 1 having its lower portionprovided with an intake 2 while its upper portion is provided with adischarge 3. In the housing 1 there are provided in superimposed andspaced relationship to each other a plurality of magnetic grates 4.These grates are so arranged that for purposes of servicing the filter,they can be removed individually from the housing 1. Between the fixedlyarranged magnetic grates 4 and above the uppermost magnetic grate, thereare provided correspondingly spaced propellers 5 which are connected orkeyed to a shaft 6 rotatably journaled in bearings 7, 8. Shaft 6 isthrough a coupling 9 drivingly connected to a transmission 10 which inits turn is drivingly connected to an electric motor 11. The bearing 8is sealed toward the outside by a stuffing box seal 12. In the upperportion of the pressure resistant housing I there is furthermoreprovided an inlet 13 for scavenging or rising water which is necessaryfor cleaning the magnetic grates 4. The water which is already in thehousing 1 may be discharged through the discharge opening 14 and thedischarge valve 15.

During the normal operation of the filter, the water to be cleaned flowsfrom the bottom in upward direction through the pressure resistant housin l as indicated by the arrows. Ferromagnetic parts or partlc es w|lldeposit on the magnetic grates 4. The propellers 5 are normally at astandstill. For purposes of cleaning the filter, the water supply isfirst shutoff and scavenging or cleaning water is admitted through theintake 2 while their propellers 5 are rotated by the motor 11 throughthe intervention of the transmission 10, the coupling 9 and the shaft 6.In this way the propellers create such a strong flow that the depositsare torn off from the magnetic grates and are washed out by the rinsingwater.

The blades of the propellers are expediently so designed that theirangle of incident or pitch may be adjusted. It is furthermoreadvantageous to arrange the propellers in pairs and so to design thesame that the propellers of each pair will run counter currently so thata strong turbulent flow will be produced. Moreover, the pitch angles ofthe individual propeller blades may be different. in this way, inaddition to creating turbulence, a slow flow to the discharge will nowbe realized. A

It may also be added that the variation of the pitch angle of thepropellers may be effected in any standard manner, at it is known, forinstance, in connection with airplane propellers.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular construction shown in the drawing butalso comprises any modifications within the scope of the appendedclaims.

What I claim is:

l. A magnetic filtering device which includes longitudinally extendingcontainer means having fluid inlet and outlet means at oppositelylocated end portions of said container means, a plurality of magneticgrate means serially arranged in said container means and spaced fromeach other in the longitudinal direction of said container means, aplurality of rotary blade means interposed between said magnetic gratemeans, and means operatively connected to said blade means forselectively rotating the same to produce a strong fluid flow along thesurfaces of said grate means.

2. A device according to claim I, in which all of said rotary blademeans are keyed to a common shaft extending in the longitudinaldirection of said container means and substantially coaxial therewith.

3. A device according to claim 1, in which each two successive blademeans are rotatable in counter current direction with regard to eachother for creating turbulence.

4. A device according to claim 1, in which the pitch angle of the blademeans is variable.

1. A magnetic filtering device which includes longitudinally extendingcontainer means having fluid inlet and outlet means at oppositelylocated end portions of said container means, a plurality of magneticgrate means serially arranged in said container means and spaced fromeach other in the longitudinal direction of said container means, aplurality of rotary blade means interposed between said magnetic gratemeans, and means operatively connected to said blade means forselectively rotating the same to produce a strong fluid flow along thesurfaces of said grate means.
 2. A device according to claim 1, in whichall of said rotary blade means are keyed to a common shaft extending inthe longitudinal direction of said container means and substantiallycoaxial therewith.
 3. A device according to claim 1, in which each twosuccessive blade means are rotatable in counter current direction withregard to each other for creating turbulence.
 4. A device according toclaim 1, in which the pitch angle of the blade means is variable.